We are requesting funds in partial support of the Gordon Research Conference on Cellular Osmoregulation and Mechanotransduction (July 5-10, 2009, University of New England, Biddeford, Maine). These funds will be used to pay conference registration and/or travel expenses for invited conference participants (including junior scientists selected on the basis of submitted abstracts as well as additional investigators selected for the excellence of their science and to foster human diversity). This conference will provide a forum for analysis of osmoregulatory and mechanotransducing systems by biophysicists, biochemists, system biologists, microbiologists, cell biologists and physiologists. Fluctuations in extracellular osmolality elicit transmembrane water and solute fluxes that profoundly perturb cell structure, cytoplasmic composition and cell function. Sensors, transducers and regulators ameliorate the consequences of those perturbations by modulating the accumulation and release of selected solutes. As mechanotransduction is not only key to cellular osmostasis but also plays a crucial role in human hearing and touch, and involves sensing of forces such as osmotic pressure, membrane stretch, vibration, and touch, these areas are included in the program. The identification of genes for osmoregulatory and mechanotransducing proteins in diverse organisms has raised important new questions that can be answered only through interdisciplinary cooperation. How are changes in osmotic pressure and mechanical stimuli sensed and processed by living cells? How do macromolecule-watersolute interactions modulate macromolecular structure, assembly and function? Which consequences of hyper- or hypo-osmotic shifts are most critical to cell function? What are the molecular mechanisms of osmoregulatory transporters and mechanosensitive channel proteins? How does a cell integrate the various regulatory mechanisms? The Conference will bring together a collection of researchers who are at the forefront of their field, and will provide opportunities for junior scientists and graduate students to present their work in poster format and exchange ideas with leaders in the field. Time slots will be reserved for the inclusion of the most recent breakthrough developments. Its inter-disciplinary focus renders this conference relevant to the missions of several Institutes including NIDDK and NIGMS. Assignment to NIDDK is proposed since it supports prominent conference participants who study mechanisms that allow kidney cells to thrive despite the fluctuating osmolality, salinity and urea concentration associated with the renal concentrating mechanism. Most cells, be it microorganisms in their natural environment or cells forming part of a human tissue, experience osmotic fluctuations. Sensing of these changes and rapidly responding to prevent cells from shrinking or expanding too much is crucial for the well being of any living species. The sensing and signaling pathways underlying the osmotic stress responses and the systems that transduce the mechanic forces in biology will be presented at the 2009 GRC 'Cellular Osmoregulation and Mechanotransduction'.